Method of conversion of vehicle bodies

ABSTRACT

A vehicle body of the convertible or targa type and the method of converting such a body from a sedan type vehicle body in which a reinforcing structure is disposed within the passenger compartment and is fastened thereto to form a centrally extending structural channel member extending longitudinally within the passenger compartment and having forward and rearward transverse portions fastened to the forward and rearward suspension supports of the body to transmit torsional and beaming loads imposed on the vehicle body by the ground engaging wheels.

This application is a division of application Ser. No. 282,078 filedJuly 10, 1981, which issued as U.S. Pat. No. 4,457,555 on July 3, 1984.

This invention relates to vehicle bodies of the type having an openpassenger compartment and particularly to the conversion of vehiclebodies with rigid roofs to such bodies.

Most automobile manufacturers have discontinued the manufacture ofvehicles of the convertible type with a soft-type top closing thepassenger compartment or of the targa type with a detachable roof panel.The apparent reason for the discontinuence of such manufacture of thosevehicles is that low volume makes manufacture uneconomical. Also suchvehicles require reinforcement to afford sufficient strength which inthe usual sedan type body is formed by a rigid metal roof panel. Thereinforcing that must be added to the convertible or targa body hasrequired the addition of substantial weight thereby undesirablydecreasing fuel efficiency. In spite of the manufacturers decisions todiscontinue the manufacture of such vehicles, a demand for convertibleor targa type vehicles continues and such demand must be met on acustomized basis by conversion of conventional sedan type bodies.

It is an object of this invention to provide a vehicle body of theconvertible or targa type which maintains proper vehicle strength forcrashworthyness and driveablity.

It is also an object of the invention to provide a method of convertingconventional sedan type vehicles to convertible or targa type vehiclebodies.

Another object of the invention is to provide a body of the convertibleor targa type and the method of making it which results in a strong bodywithout the usual increase in weight of the body.

Yet another object of the invention is to provide a vehicle body of theconvertible or targa type and the method of making it in which a tunnelis incorporated substantially longitudinally and centrally of thevehicle to absorb bending and torsional loads.

A further object of the invention is to provide a vehicle body of theconvertible or targa type and the method of making it in whichmodification is accomplished from the interior of the vehicle

Basically the invention provides a vehicle body of the convertible ortarga type in which a reinforcing member is installed within thepassenger compartment and is joined to the floor pan, the forward andrearward sub-frame to form a central tunnel-like construction havingforward transverse and rearward transverse members absorbing loadsimposed by the wheels and transmitted through the suspension system tothe forward and rearward sub-frame. The reinforcing structure has agenerally U-shaped configuration and the main portion extends generallylongitudinally of the vehicle and overlies an exsisting tunnel structureto form a closed tube for absorbing torsional and bending loads. Thereinforcing structure has a height no greater than the seat membersdisposed at opposite sides so that a maximum cross-section is obtainedto afford strength. The reinforcing structure includes specificallyformed joints which prevent buckling and further add strength and at thesame time keep weight at a minimum.

The preferred embodiments of the invention are illustrated in thedrawings in which:

FIG. 1 is a diagrammatic side elevation of a sedan type vehicle which ismodified in accordance with principals of the invention;

FIG. 2 is a diagrammatic cross-sectional view taken generally on line2--2 in FIG. 1 and at a slightly enlarged scale;

FIG. 3 is a top view of the floor pan of a vehicle body being modified;

FIG. 4 is a side elevational view of the vehicle in FIG. 1 after the tophas been removed;

FIG. 5 is a partial view of the vehicle seen in FIG. 4 with parts brokenaway and removed;

FIG. 6 is a perspective view of a portion of a floor pan of a vehiclebody;

FIG. 7 is a perspective view of the reinforcing structure which isinstalled in the vehicle body;

FIG. 8 is a view of the reinforcing structure of FIG. 7 with the partsin exploded relationship;

FIGS. 9, 10 and 11 are cross-sectional views at an enlarged scale takengenerally on lines 9--9, 10--10 and 11--11, respectively in FIG. 7;

FIG. 12 is a perspective view of a portion of the vehicle body duringthe time that it is being modified;

FIG. 13 is a view of another form of sedan vehicle which is modified;and

FIG. 14 is an exploded view of a vehicle body of the targa type whichalso embodies the invention.

In accordance with the preferred embodiment of the invention aconventional sedan type body indicated at 10 in FIG. 1 is modified andconverted into a convertible body indicated generally at 12 in FIG. 4 ortarga body indicated at 13 in FIG. 14. Referring to FIGS. 1 and 2 thesedan body 10 is of the self-supporting or unitized type and includes afloor pan 14. Typically such bodies have rocker panels 16 at oppositesides which serve to reinforce the floor pan. Also usually a tunnel 18opens downwardly and is disposed centrally of the vehicle. As seen inFIG. 6 such a tunnel 18 may take an irregular shape and can be used forthe purpose of housing a drive shaft for rear wheel drive vehicles orthe exhaust system for front wheel drive vehicles. The longitudinallyextending tunnel 18 serves to strengthen the floor pan 14 in alongitudinal direction. The floor pan 14 also is formed integrally witha forward sub-frame made up of a pair of side sub-frame members 20 and arearward sub-frame made up of a pair of rearward sub-frame members 22.The forward and rearward sub-frame members 20, 22 form the foundationfor the suspension system (not shown) which includes the ground engagingwheels 24.

The floor pan 14 also is shown as including a formed cross member 25which extends from the tunnel 18 to the rocker panels 16 at oppositesides of the floor pan 14. The cross members 25 serve to reinforce andstiffen the floor pan and act as a support or anchor for such equipmentas seats 26 and for safety belts, not shown.

The forward portion of the floor pan typically slopes upwardly andforwardly of the front wheels 24 to form a firewall 27 separating theengine compartment 28 and the passenger compartment 29. The rear portionof the floor pan 14 has a slightly elevated deck 30 merging with thetunnel 18 and forming a support for rear seats, not shown.

The remainder of the body sheet metal is formed integrally with thefloor pan 14 and includes a sheet metal roof 31 supported in elevatedposition above the passenger compartment. The support for the roof 31 isin the form of a pair of forward pillars, commonly referred to as "A"pillars and so designated in the drawings, disposed at opposite sides ofthe vehicle to form opposite sides of the windshield 32. The rear of theroof 31 is supported by integral side panels 33 disposed at oppositesides of the body and acting to form opposite sides of a rear window 34.An intermediate portion of the roof is supported by a pair of "B"pillars disposed rearwardly of the doors 36. The "B" pillars and theside panels 33 frame oppostie sides of rear, side windows 35.

The doors 36 may be provided with an upper frame 38 for framing asliding window glass panel or light 40. The glass in the windshield 32,the door window 40 and rear window 34 have their lower edgessubstantially horizontally aligned along a line called a belt-line anddesignated at 42 in FIG. 1.

The various loads imposed on the sedan body 10 by the wheels 24 areabsorbed through the floor pan and the roof 31. The strength necessaryto transmit loads between the forward and rearward wheels is referred toas beaming strength, that is the strength necessary to resist distortionof the body between the front and rear wheels. The ability of the bodyto absorb diagonal loads between the front wheel at one side of thevehicle and the rear wheel at the opposite side of the vehicle isreferred to as torsional strength.

Conversion of the vehicle body 10 is conducted from the interior of thebody so as not to interfere with the under body structure andattachments such as the drive train, suspension, and the like. Theconversion begins with the interior of the passenger car body 10stripped of all interior trim such as carpeting, mats, moldings and thelike. Also, the seats are completely removed.

Conversion continues with the installation of a reinforcing structure 46which includes a main center section 48, a forward section 50, a rearsection 52 and a pair of rear extension members 54. All of the sectionsare of generally irregular, symmetrical configurations but have portionsforming inverted U in cross sections.

The center section 48 is an inverted U shape cross section which as seenin FIGS. 9, 10 and 11 taken at different transverse sectional lines inFIG. 7, has a vertical height greater than the corresponding section ofthe tunnel 18. Also the tunnel section 46 has outwardly and oppositelyextending flange portions 56 which are adapted to engage the floor pan14 and to be fastened thereto. Fastening preferrably is conducted by theuse of rivets 58. Additionally, the flange can be secured to the floorpan by the use of a structural polyurethane adhesive sealant between theflange portions 56 and the floor pan 14. Also, tunnel structures may bewelded instead of riveted. With all methods of connection, the centersection 48 forms a closed tubular structure with the tunnel 18.

The forward section 50 of the reinforcing structure 46 includes a tunnelportion 59 having a configuration at its rearward end conforminggenerally to the forward end of the center section 48 and in additionhas a pair of oppositely extending wing portions 60 which are formedintegrally with the forward section 50. As seen in FIGS. 7 and 8, thewing portions 60 are reinforced by a plurality of downwardly openingreinforcing channels 62 which when fastened to the floor pan 14 formclosed tubular structures for adding strength and rigidity to the mergedconstructions. Like the center section 48, the forward section 50 hasflanges 64 around its perimeter which aubt the surfaces of the floor pan14 and are connected thereto by means of rivets 58 and adhesive.

The rear section 52 of the reinforcing structure 46 has a U-shapecentral section 65 which merges with laterally extending portions 66 theoutboard ends of which are adapted to be joined with the pair of rearextensions 54. Both the rear section 52 and the side extension 54 areprovided with flanges 70 which are adapted to be fastened with rivetsand adhesibe to the floor pan 14. In addition, the rearward section 42is provided with a rearward transverse flange 71 which is adapted to befastened by way of adhesive and rivets to the rear deck 30. The sideextensions 54 are provided with flanges 72 which are fastened by way ofrivets and if desired, adhesive to the rear deck 30 and to the rearsub-frame members 22.

The rear section 52 is joined to the center section 48 by means of ajoint construction which adds rigidity and helps to absorb torsionalloads that are imposed on the tunnel structure 46. As best seen in FIG.8, the joint includes a channel portion 74 formed adjacent the rear endof the center section 48. Opposite sides of the channel portion 74 areprovided with seating surfaces 76 which abut the inside surface of theforward portion 65 of the rear section 52. The seating surfaces 76 andthe rear section 52 can be joined together by welding or by the use ofrivets and when so joined the composite structure forms a tubularconstruction affording great strength and rigidity in relation to theweight of the material used and acts to prevent buckling when largeloads are imposed.

The outboard ends of the lateral extension 66 of the rear section 52 arealso provided with a construction including channel portions 78 andseating surfaces 80 which are joined to the side extensions 54 in thesame manner that the center section 48 is connected to the rear section52. Again, this construction adds great strength with minimum weight.

Additional rigidity and strength can be obtained by the use of elongatedmembers 82 seen in FIGS. 7 and 8 having a generally hat-shaped crosssection. The members 82 are attached by welding or rivets to the insidesurfaces of the tunnel structure 46 and form additional tubularreinforcing portions.

In some instances the reinforcing structure may be further strengthenedby providing transverse bulkheads 83, 83a or 83b as seen in FIGS. 9, 10and 11, respectively. The bulkheads 83, 83a and 83b have flanges 85around the periphery of the bulkheads and which are attached to thetunnel 18 and reinforcing structure 46 by means of rivets or welding.Such bulkheads act to prevent buckling of the reinforcing structure.

In addition to the described manner in which the reinforcing structure46 is connected to the floor pan 14, it also is connected directly tothe reinforcing portions of the floor pan 14 such as connection of theforward section 50 to the forward sub-frames 20, the center section 48to the cross members 25 and the rear section 52 to the rearward subframe22. This connection also is made by way of rivets 58 or welding.

In addition to the described manner in which the reinforcing structure46 is fastened to the floor pan 14, the forward section 50 is connecteddirectly to the forward sub-frames 20, the center section 48 isconnected to the cross-members 25 and the rear section 52 is connecteddirectly to the rearward sub-frame members 22. These connections alsoare made by way of rivets 48, and adhesive or by welding.

With the passenger compartment stripped of all lining materials toexpose metal surfaces the reinforcing structure 46 can be installed.Preferably the center section 48 is installed followed by the additionof the forward and rearward sections 50 and 52 and the rearwardlyextending sections 54. The connections are made by way of riveting andadhesive but welding may be used if reinforcement is installed prior tosheet metal painting.

After the reinforcing structure 46 is installed within the passengercompartment 29 of the body 10, removal of the top metal can beinitiated. This can be accomplished by removal of all of the glass whichincludes the glass in the windshield 32, rear window 34, the sidewindows 35 and door windows 40. Thereafter the body 10 can be cut with ametal saw along the belt line 42 to sever the "B" pillars and sidepanels 33. In addition the roof panel 31 can be cut immediatelyrearwardly of the windshield header 84 and thereafter can be removedfrom the remainder of the body 10. In some conversions the "A" pillarsforming opposite sides of the windshield 32 are cut at a line indicatedat 86 and the windshield header 84 also is removed. In that case, thestep of cutting the roof panel 32 rearwardly of the windshield header 84can be omitted and the "A" pillars can be severed at the cut 86 andremoved together with the roof panel 31.

With the roof construction and windshield header 84 removed the body canbe further refined by the addition of a new windshield header 88particularly adapted for receiving and detachably connecting to theforward edge 90 of a convertible, foldable and retractable topconstruction 92. The addition of a new header 88 makes it possible tolower the roof line of the convertible body 12 if so desired by removinga section of the "A" pillars.

In addition to removal of the roof structure 31 in some vehicles havinga framed door 36 it is necessary to modify the doors by removing theframes 38. This also is accomplished by cutting along the belt line 42.Conversion of a framed door is more fully described in co-pendingapplication of the assignee of the present application but in briefentails removing the frame 38 by sawing along the belt line 42, byremoving the glass forming window 40 and by substituting a new glass toaccomodated the lowered roof line and the space fomerly occupied by thewindow frame 38.

In order to accomodate the folding top 92 a rearward portion of thepassenger compartment is provided with a bulkhead 94 as seen in FIG. 12which forms a cavity 96 to receive and to store the folding top 92. Theinterior of the passenger compartment can now be covered with carpetingand with lining material to cover all of the exposed surfaces and a rearseat may be included. Forward bucket seats 26 are installed in aconventional manner at opposite sides of the center section 48 of thetunnel structure 46. As seen in FIG. 1 the seating surface has a heightapproxiamtely equal to the height of the tunnel structure 46. This makesit possible to obtain the maximum cross sectional area for the tunnelstructure 46 to enhance its torsion absorbing capabilities.

Referring now to FIGS. 13 and 14, another embodiment of the invention isshown in which a two-door sedan type vehicle body 110 is converted to atarga type body 13. A targa type body is one in which the roof iscompletely removable to form an open passenger compartment as seen inFIG. 14. Vehicles of this type also are subject to beaming and torsionalloads which must be resisted by structure added to replace the typicalintegral roof panel 116.

The sedan body 110 is slightly different than the vehicle body 10 butcan be considered as incorporating a floor pan and suspension supportsvery similar to the floor pan 14 and suspension supports 20 and 22.

In this embodiment of the invention, the interior of the passengercompartment is stripped of all carpeting, lining and moldings to exposethe metal surfaces after which a reinforcing tunnel structure 46 isinstalled in the same manner as in the body 10. Thereafter, the roof 116is cut immediately to the rear of the windshield header 118 and along aline 119 substantially in alignment with the rear edge of the upperportion of the door opening. Thereafter, a forward frame member 122 isattached to the metal edge immediately to the rear of the windshieldheader 118 and a rearward frame member 124 is attached to the cut edge119 to the rear of the opening formed by removing the roof section. theframes 122 and 124 can be additionally modified to receive seal membersengageable with the detachable panel 114.

It will be noted that in both embodiments of the invention, thereinforcing tunnel structure 46 is installed prior to any modificationof the roof 31 or 116. In this manner, the original structural integrityof the body 10 or 110 can be maintained without the necessity ofblocking or otherwise supporting the vehicle body.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. The method of convertinga sedan passenger automobile body which includes a continuous roofpanel, a floor pan and suspension supports formed integrally to eachother, the steps comprising: adding a reinforcing structure having achannel member with inverted U-shaped cross-sections centrally andlongitudinally within the interior of said body, fastening said channelmember to said floor pan, adding a forward transverse reinforcing memberwithin the interior of said body and fastening it to the channel member,to the floor pan and to the forward suspension supports, adding arearward transverse member to the interior of said body and fastening itto the channel member, to the floor pan and to the rear suspensionsupports, cutting and removing the continuous roof panel completely fromone side of said body to the other and along the sides of the continuousroof panel, and replacing a detachable roof panel in the cut awayportion of the continuous roof panel.
 2. The method of claim 1 whereinthe forward portion of the removed roof panel is cut along a lineadjacent the windshield header.
 3. The method of claim 1 wherein thedoors on said vehicle have a framed window and wherein said frame isremoved by cutting along a line at the lower edge of said windowopening.